Many medical procedures require repeated and prolonged access to a patient's vascular system. For example, chemotherapy, paraternal nutrition antibiotic regimens, blood withdrawals and other similar treatments require such repeated access to the patient's vascular system. It is impractical and dangerous to insert and remove the catheter for each session. Thus, the needle and catheter are generally implanted semi-permanently with a distal portion of the assembly remaining within the patient in contact with the vascular system while a proximal portion of the catheter remains external to the patient's body. Alternatively, the proximal portion may be implanted subcutaneously with a port formed therein for access via, for example, a syringe. In many cases, such a port will be implanted subcutaneously in the patient's arm or chest, to keep it protected while affording easy access, and consists of a housing with one or more wells to receive the therapeutic agents.
It is often necessary to infuse into the patient therapeutic agents that are not compatible with each other. For example, certain chemotherapy agents are incompatible with one another and, therefore, require special handling during therapeutic sessions. In some cases, the therapeutic agents are fluids that cannot be mixed together outside of the body, but which will preferably be infused together or within a certain period of time. Some of these fluids cannot be infused through the same lumen because they may coagulate or form a precipitate that clogs the port or catheter lumen. In other instances, the fluids may be incompatible for other reasons, and are therefore kept separate until they reach the patient's blood stream. This has conventionally been achieved by employing, for example, a separate catheter for each of the agents with distal ends of the catheters opening to the bloodstream in proximity to one another. Alternatively, a dual lumen catheter may be used, with each lumen containing a different one of the agents.
Providing two unmixable therapeutic fluids to a dual lumen catheter or to two separate catheters near each other presents challenges, since a conventional port cannot be used to inject both fluids. Ports are generally not implanted near one another because of the surgery required to insert each port in place, and the additional complications that may arise as a result of the port residing in an area. A dual well port device may be used, with two ports formed within a single housing, each port being connectable to a different catheter or to a different lumen of a dual lumen catheter. However, conventional dual well port devices are larger than single port devices, and may be difficult to place in the patient's body. In addition, an adapter is often required to connect a dual lumen catheter to conventional dual well port devices, because the distance between the outlets of the dual well port device is greater than the separation between the two lumens of the catheter.